Many constructions of ostomy bags are known and many of them are secured to the patient by means of special carrying, holding or coupling means. It is also well-known to provide ostomy bags in some manner or other with filters to deodorize flatus. Such filters may be built into the bag or they may be separate and adapted to be placed over a permanent opening in the bag or one formed for the occasion. In the former case the filter is always discarded together with the bag, in the latter the same is often the case but not always.
Many different holding or coupling means for affixing to the skin of the patient are known, e.g. by adhesion or by the aid of a belt, and many of them are. adapted to releasably receive an ostomy bag, e.g. by means of suitable coupling rings or other coupling elements, or adhesively. Such holding or coupling means as a rule may be used several times, which firstly is an economic advantage because such a means is a comparatively costly element in the overall ostomy bag arrangement, and secondly because thereby they can remain in place on the skin of the patient around the stoma for a comparatively long period of time, which is advantageous because the replacement of the holding means frequently may cause discomfort or even pain.
The filter is also a comparatively expensive part of the ostomy bag arrangement and it is therefore advantageous to build it into the holding or coupling means.
A few examples of doing this are known. Thus, GB patent specification No. 1,595,906 describes a surgical dressing having a carrier pad one side of which can adhere to the skin of the patient and the other side of which is provided with a first coupling member whereby a colostomy bag can be secured to the pad by means of a second coupling member secured to the bag, all provided with apertures which can be aligned with the stoma to allow intestinal contents to flow into the bag. The specific feature of this dressing is that a gas passage path extends through the pad or the first coupling member to the outer world, all of the gas passage path extending substantially vertically upwardly when the pad is being worn normally by an upright patient, the portion of the gas path placed in the pad or the first coupling member having a gas filter inserted. The gas filter is, as nearly always and also according to the present invention, based on activated carbon.
A similar construction is known from U.S. Pat. No. 4,232,672. Although it is not said in the claims of that patent that a filter compartment has to turn upwardly during use, this is clear from the description. The main difference relative to the above-mentioned GB patent is that one or more ducts lead from the interior of the bag to the filter compartment and that these ducts may be closed by a valve arrangement which via a resilient member is connected to a push button; only when this is activated, flatus will escape from the bag. From GB patent specification No. 1,212,904 there is also known a holding means for ostomy bags, this means provided with a flatus discharge duct which may be closed by a valve. In this case there is no gas filter in the duct.
It is a disadvantage of the known constructions mentioned that they need to have the holding or coupling means situated at the skin of the patient at a definite orientation, firstly because this may be difficult, secondly because the vertical orientation only exists when the patient is standing or walking, but not when he is lying, especially not when he is lying on his side. It is advantageous to be able to close the gas discharge duct when is does not contain a gas filter, but otherwise it is comparatively unimportant or even a disadvantage (if one forgets the venting, the bag will be inflated by flatus), and in both cases the valve arrangement is relatively complicated and at any rate it will increase the cost.